A semiconductor integrated circuit of the related art includes a power supply switch circuit provided between a power supply line to which an input power supply voltage is applied, and a power supply line of a load circuit. As a way to decrease the current as much as possible, the power supply switch circuit is turned off except when it is needed by the load circuit for operation. Also, the power supply voltage of the load circuit is required to rise quickly when necessary and an inrush current needs to be suppressed in such a manner that the rising of the power supply voltage of the load circuit does not inadvertently cause an operation for protecting against inrush currents to be performed.